Today, a new front opens in the law around polygamy as Kody Brown and his 4 wives, stars of the ‘Sister Wives’ reality-TV show, file suit in Salt Lake City to challenge the law Utah uses to suppress polygamy.

The Browns were seen in the second series of the show relocating their family to Las Vegas in an effort to escape an investigation by police in Utah as a result of their coming out as polygamists on national television.

The law in Utah criminalises bigamy, as in much of the Western world, but unlike many other areas uses a cohabitation provision to make polygamists vulnerable to prosecution even where they have been careful only to have one legally recognised wedding. The effect is that all polygamous relationships where the husband lives with his wives are criminalised in Utah, whereas in most other Western legal systems, including many other American states, polygamy can be practised without committing a crime as long as polygamists do not use official wedding ceremonies more than once.

Prosecutions for polygamy are rare in Utah, despite the number of polygamists in the state being estimated in the tens of thousands, as the State recognises it does not have the resources to investigate, prosecute and imprison polygamists in that number, and the law governing polygamy is constitutionally questionable. Prosecutions have tended to involve those who have committed other offences, or those who have drawn attention to themselves in the media, leading to an effective “don’t ask, don’t tell” approach by the authorities.

Kody Brown and his wives Meri, Janelle, Christine and Robyn will file the suit in the federal court today before making themselves available for questions outside the courthouse at 1 p.m.

The Brown family are represented by Jonathan Turley, a constitutional law professor at George Washington University who recently submitted expert evidence to the polygamy reference case in British Columbia, where a similar law is being challenged as allegedly breaching Canada’s Charter of Rights and Liberties.

Professor Turley said of the Brown Family case, “We believe that this case represents the strongest factual and legal basis for a challenge to the criminalization of polygamy ever filed in the federal courts. We are not demanding the recognition of polygamous marriage. We are only challenging the right of the state to prosecute people for their private relations and demanding equal treatment with other citizens in living their lives according to their own beliefs. This action seeks to protect one of the defining principles of this country, what Justice Louis Brandeis called ‘the right to be left alone.’ In that sense, it is a challenge designed to benefit not just polygamists but all citizens who wish to live their lives according to their own values – even if those values run counter to those of the majority in the state.”

For his part, Kody Brown said “There are tens of thousands of plural families in Utah and other states. We are one of those families. We only wish to live our private lives according to our beliefs. While we understand that this may be a long struggle in court, it has already been a long struggle for my family and other plural families to end the stereotypes and unfair treatment given consensual polygamy. We are indebted to Professor Turley and his team for their work and dedication. Together we hope to secure equal treatment with other families in the United States.”

It is likely that the Brown’s case will build on the U.S. Supreme Court’s 2003 decision in Lawrence v. Texas, where the majority ruled that the state could not prosecute people for engaging in private, consensual sexual behavior — in that case, gay sex. Justice Antonin Scalia issued a minority judgement criticising the majority for opening the way to decriminalisation of polygamy and other behaviours.

National Public Radio reports Princeton University’s Robert George as commenting, “State laws to protect public morality by prohibiting what have been regarded as immoral sexual conduct just can’t stand constitutional scrutiny. So, if they accept the logic of their own principles, then Turley is going to win this in a knockdown”

That however, is a big ‘if’. Will liberal Supreme Court Justices really be prepared to tell the anti-gay-rights lobby that their slippery-slope arguments about gay rights and polygamy were right all along, and is conservative justice Scalia suddenly going to accept the reasoning of Lawrence v Texas, which he explicitly rejected at the time it was decided. We will wait and see.

In the meantime, a decision is expected in the next few weeks as to whether the State of Utah is to prosecute the Brown family. Will Utah be prepared to prosecute someone they normally wouldn’t, just because they are on television? Does that raise the prospect of the influence of the mainstream Mormon church in Utah clamping down on the fundamentalist versions of their faith in a style reminiscent of the last series of Big Love. Could the state countenance not prosecuting such an obvious breach of their laws, and would that not raise the question of, whatever the Courts say, polygamy actually not being capable of prosecution?

Whatever happens, there will be an opportunity for some constitutional tidying-up, and a massive public relations exercise for modern polygamy. The Browns, with their 16 children, and 2 television series under their belt, are a family who have chosen themselves, and are much more palatable to the public than the various miscreants, rapists and child-abusers the state has usually selected for polygamy prosecutions.

At this stage, all that is being asked for is freedom from prosecution from living like married people. There is no request for the law to recognise or regulate polygamous marriage, although many Western countries do this in at least some form already. It would be possible to forget that in most places the Brown’s lifestyle would be perfectly legal, but the fact that many areas have a law with a similar name as those in Utah and British Columbia gives the impression that polygamy itself is illegal in many more areas than is actually the case. If this lawsuit does nothing else, it gives an opportunity for that to be addressed.